Electric furnace



2 Sheets-Sheet 1 FISQ.

Jan. 3', 1928.

P. .1. MIGUET ELECTRIC FURNACE Filed sept. 29. 192ewww Jan. 3, 1928. i 1,655,324

P. L. J. MIGUET ELECTRIC FURNACE Filed sept. 29, 192e 2 Sheets-Sheet 2.

Plc-5.7

Patented Jan. 3, 1928.

unirse srarns TENT GFFICE.

PAUL LOUES JSEzI-I IvIG-UET, F Sill-o UnIEN-DE-YIAURIENNE, FRANCE, ASSIGNOR TO SGCIETE ELECTROMETALLURGQUE DE MONTRICHER, OF ST.J'ULIEND E-MAU RIENNE, FRANCE.

ELECTRIC FURNACE.

Applicationinled September 29, 1926, Serial No. 138,540, and in France December 31, 1925.

This invention relates to electric reducing furnaces and more especially to the econoniic running of high power furnaces with high production.

According` to one object of the invention,

sandwiched conductors` connecting' the basel of the furnace body and the electrode are arranged in ducts or flues arranged outside the furnace walls` a current of cooling' air circulating through said ducts, Without the air entering' the furnace lining' and ineans being provided for support-ing the ducts and their cooperating parts independently of the furnace body.

The exterior ducts allow for the suppression of all danger of the ignitingr of air in the combustible portion of the apparatus, for the arrangement of transformers on the sides of or under the furnace andthe free access to the upper portion of the furnace.

According to a second object of the invention, the Walls of the furnace body are surrounded by a Water-cooled lining' and by nietal sleeve, preferably lead, rendered airtight by autogeneous Welding when in place, allowing the suppression of all heart radiation in the lower partof the furnace, the prevention of expansion of the Walls, the gradual Wearing away of the apparatus and, finally, the prevention of the ent fance of stray air, capable of provoking' slow combustion in the flue.

According' to a third object of the invention, the furnace body is supported by a hollow pillar, preferably of reinforced concrete, through holes, provided in its top, coolingr air is blovni.y Which passes then through the exterior chiots.

glther objects of the invention will a ppear in the description with reference to the accompanying drawings, given by way of example.

Figs. l and 2 are respectively a vertical half section and a part section on a plane inid-vvay up the chamber' of an electric furnace. p

Figs. 3 and e are section elevation and sectional plan of a continuous electrode.

Figs. 5 und 6 are. similar views showing a. modification of a hollow electrode.

- conductors e Fig. 7 is a sectional elevation of a hollow electrode.

Figs. 8 and 9 show respectively a sectional plan and elevation of a protecting' shield.

Figs. l() and li are respectively a side elevation and half sectional elevation of the n'ieans for holding the sheet iron screen away froni the rods. n

Ivins.V l and 2 show a duct l preferably arraned along' a nietal plate 2 projecting belenw the floor 3 supporting` the apparatus independently of the furnace Walls improving the service including the sandwiched connecting' the base of the chaniber 5 and the electrode 6 through a lateral transformer introduced at l or through a transformer at S. The sheet iron plates 9 are arranged in such a way that air blown through theni at 10 passes through the chamber containing the transformers, passes over thein and escapes at li Without there being' any chance of its entering the lining 12.

Cooling` plates 13 and ist in contact With Water circulation tubesv l5 project at the upper level of the furnace Where they are provided with inlet and outlet connections only taking up enough rooin transversely inside the walls for the necessary cooling of the lead sleeve 16 made airtight by soldering in situ. The sleeve l0 is so arranged that the vertical plates lying adjacentto them, project at their upper ends and cannot cut theni with their rough lower edges as these are sunk.

The side and end plates naturally forni on the one hand a casing` only liollov,lv to the right of the cast chamber and on the other a plane disc concentric with the oven so that uniforin coolingy is obtained.

A hollow pillar 17 the height of which varies according as to Whether the transformers are arranged laterally or on end allows for a considerable reduction in the importance of the reinforced lining' 1S and consequently increases the eiciency of the supplementary air cooling through the ducts l regulated by the dempers lO.

F 3 and show respectively a sectional elevation and plan of a continuons electrode built up from sections, preferably slotted segments 19, dovetailed together at 20 and secured by bolts 21 having countersunk nuts at both ends. y The filling of the slots between the segments and aA central channel with powdered carbon is only done the last thing.

The similar arrangement having transverse bolts-21 and aV central passage lined with a metal tube 22 for thevpassage of gas and vapour from the furnace.

Fig. 7 is a vertical section of a hollow electrode 22 formed in segments held in position by lateral bolts but discontinuous as it has a condensing chamber 23 preferably provided with a suitable interior lining 2dr separa-ted fromthe electrode'by refractory wall 25 of variable thickness. Tliesuction of the gas and vapour is maintained by a pipe 26 the exhaustion of the condensed products being through a tube inserted into the passage 27. The electromechanical continuity of the whole is assured by a cooled ring 28 formed with powdered carbon on the face next tothe base electrode and the base of the condenser casing. l Figs. 8 and 9 show respectively a. sectional elevation and plan of the protecting shield having `a double bottom 29 water coole-d .through tubes and supported by rods 31 resting directly on the leads 32.v

i Figs. 10 and 11 show respectively a sideV elevation and-a half sectional elevation of a sheet iron'screen 33 preferably mounted on hanging rods 34. by lugs and affixed thereto by a washer 36. rlhe exterior duplication of the screens allows for a better eniciency lofthe hanging rods, without deformation of the sheet screens, which are not subjected to the direct radiation of the furnace.Y

What I claim as my invention and desire to protect Vby Letters Patent is Y 1. An electric reducing furnace comprising ducts arranged outside the ywalls sandwiched conductors disposed within the ducts whereby these latter may be air cooled without the air entering the furnace lining` transformer chambers Vin the ducts and means for supporting the apparatus independently of the furnace walls.

2. A cylindrical electric reducing furnace as in claim V1 having cooling plates and a lead sleeve arranged around the outer walls thereof at the sides and front. Y

3. An electric reducing furnace asin claim 1 having a hollow pillar through which air can be blown supporting the walls and thc high tension apparatus. I 1

Li. An electric reducingV furnace as in claim 1 having screens of hanging rods and corrugated shee-tjiron,

5. An electric reducing furnace, comprising an electrode extending downwards in a Figs. 5 and 6 show a modified Y and means for supporting the ducts and their cooperating parts independently of said walls. l v

6. An electricreducing furnace, comprising an electrode extending downwards ina chamber, duc-s arranged outside the walls of said chamber, sandwiched conductors disposed within said ducts, transformer chambers vcommunicatin'g` with said ducts, means for blowing airthrough said ducts and said transformer chamber without the air entering the walls of said Ychamber and means for supporting the ducts and their cooperating parts independently of said walls.

7. An electric reducing furnace comprising'an electrode extendingy downwards in aV chamber,air cooled ducts arranged outside the walls of said chamber, sandwiched conductors disposed within said ducts, means for supporting the ducts and theirvcoop'erating parts independently of said walls and a liningof water cooled plates arranged at the outside of said walls.

8. An electric Vreducing Vfurnace comprising an electrode extending downwards in a chamber, air cooled ducts arranged outside the walls of said chamber, sandwiched conductors disposed within said ducts, means for supporting the ducts and their cooperating parts independently of said walls a 'lining of water cooled plates arranged at the outside of said walls and an air-tight metal A sleeve embedded in said walls.

9. An electricV reducing furnace compris- ,ing an electrodeiextending downwards in a;

chamber, a pillar supporting the walls ofv said chamber ,air cooled ducts` arranged outside said walls, sandwiched conductors disposed within said ducts, means, vindependent of said pillar, for supporting the ducts and their cooperating parts.

10. An electric reducing furnace comprising an electrode extending Vdownwards in a chamber, a hollow Vpillar supporting thel Vwalls of said chamber, ducts arranged outside said walls, sandwiched conductors dis` posed within said ducts, transformer chainbers communicati-ng with said ducts, means for blowing air through the hollow pillar. thel ducts and the transformer chambers and means, independent fof said pillar, for supporting the ducts and their cooperating parts. Y V

11. An electric reducing furnace comprisingV a. tubular electrode extending downwards in a. chamber, sandwiched air cooled conductors arranged in ductsoutsidethe walls of saidchamber and supported independently ofY said walls, a condensation chamber 'arranged above said electrode, a tube therefrom for drawing vapors from said condensation chamber and a second t-uhe therefrom through which condensed products are exhausted.

12. An electric reducing furnace compris- 5 ing an electrode extending` downwards in a chamber, sandwiched air cooled conductors arranged in ducts outslde the Walls of said In Witness whereof I aiix my signature.

PAUL LOUIS JOSEPH MIGUET. 

